There are already known wristwatches provided with a pressure measuring device. These wristwatches, for example diver's watches, conventionally include a pressure sensor, for example a membrane sensor whose deformations vary with pressure fluctuations encountered during dives. In a known embodiment, the variation in geometric dimensions of the pressure sensor with atmospheric pressure fluctuations is converted into the linear motion of a sensing arm, which controls the pivoting of a lever. The pivoting motion of the lever is in turn converted into the rotational motion of a gear train which meshes with a display wheel in a drive ratio calculated such that a pressure indicator hand carried by the display wheel provides the user of the watch with a legible pressure indication.
Constructions of the type briefly described above are typically used to provide the user of the watch with a pressure indication during a dive.
These mechanical pressure measuring and display devices are relatively complex and difficult to implement given the large number of mechanical parts comprised therein. Further, they require communication to be provided between the exterior of the watch case and the interior where the device is mounted which results in complex arrangements if the sealing of the watch is required to be guaranteed in all circumstances. These factors thus make it difficult to produce watches fitted with mechanical pressure measuring and display devices in an economical manner.
It is a main object of the invention to provide a pressure sensor that is simple and economical to implement.
It is also an object of the invention to provide a pressure sensor having a structure which allows it to be easily integrated in a portable object of small dimensions, and particularly in a watch, without affecting the sealing thereof.